JPS5930179B2 - Rubber composition for vulcanization - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vulcanizable rubber composition, and more particularly to a vulcanizable rubber composition comprising a combination of different types of ethylene/α-olefin copolymer rubbers.

It is a well-known fact that vulcanizates made from ethylene and α-olefin copolymer rubbers are used in a wide variety of fields because of their excellent weather resistance, heat resistance, electrical properties, and rubber properties. In the commonly used ethylene/α-olefin copolymer rubber, the α-olefin is propylene, and the molar ratio of ethylene units to propylene units (ethylene/propylene) is 50,150 to 82/18. Rubber or ethylene-propylene-polyene copolymer rubber.

However, such general ethylene-propylene copolymer rubber vulcanizates still have many unsatisfactory points.

That is, although the strength of the vulcanizate of the copolymer rubber can be improved to some extent by incorporating a rubber reinforcing agent such as carbon black, there is a limit. In addition, by incorporating an extremely inexpensive filler such as calcium carbonate, an inexpensive vulcanizate can be obtained, but on the other hand, the strength of the vulcanizate is extremely reduced. On the other hand, the present inventor has developed a material that solves these drawbacks by using ethylene and carbon atoms with a carbon number of 4.
A copolymer rubber with the above α-olefin, which has a molar ratio of ethylene units to the α-olefin units (ethylene/
Ethylene and α-olefin) with approximately 90/10
It was found that the vulcanizate of olefin copolymer rubber has significantly higher strength than the vulcanizate of ethylene/propylene copolymer rubber with the same molar ratio, and has considerable rubber-like properties. - It was found that the rubber properties of vulcanizates made from α-olefin copolymer rubber deteriorate at low temperatures, such as increased compression set, increased hysteresis loss, and decreased flexibility.

Therefore, the first object of the present invention is to provide a composition that provides a vulcanizate with higher strength than that of ordinary ethylene-propylene copolymer rubber. Another object of the present invention is to provide a composition with which a vulcanizate having strength equivalent to that of conventional ethylene-propylene copolymer rubber can be produced at a lower cost. molar ratio of α-olefin units from 1 to 10 (
Taking advantage of the inventor's knowledge that a vulcanized product of ethylene/α-olefin copolymer rubber with a ratio of about 90/10 (ethylene/α-olefin) has extremely high strength, the vulcanizate has sufficient rubber-like properties even at low temperatures. The present invention relates to providing a composition capable of providing sulfur. That is, in the present invention, the molar ratio of ethylene units to α-olefin units having 3 to 10 carbon atoms (ethylene/α-olefin) is 50/50 or more.
Ethylene/α-olefin copolymer rubber A that is less than 2/18 and the molar ratio of ethylene units to α-olefin units having 4 to 10 carbon atoms (ethylene/α-olefin) is 82/18 to 95/5. consisting of a certain ethylene/α-olefin copolymer rubber B, and the weight ratio of the copolymer rubber A and the copolymer rubber B (copolymer rubber A/copolymer rubber B) is 5/95 to 95/5. The present invention relates to providing a rubber composition for vulcanization characterized by the following. The composition of the present invention has good roll processability and extrusion moldability, so there are no manufacturing problems, and a vulcanizate with higher strength than conventional ethylene-propylene-polyene copolymer rubber vulcanizates can be obtained. , it is possible to obtain a vulcanizate that takes advantage of the extremely high strength of the copolymer rubber B and has considerable rubber-like properties even at low temperatures. Since the decrease in strength is small, a vulcanizate having the same strength as the ethylene-propylene-polyene copolymer rubber manufactured by Jumei can be obtained at a lower cost. The advantages and configuration of the present invention will be better understood by describing the present invention in more detail below.

α-olefin, which is a component of the ethylene/α-olefin copolymer rubber A used in the present invention, has 3 to 10 carbon atoms.
α-olefin.

Specifically, 1-butene, 1-benzene, 1-hexene,
Examples include 4-methyl-1-benzene, 1-octene, 1-decene, and mixtures thereof, among which propylene is preferred. The molar ratio of ethylene units and α-olefin units (ethylene/α-olefin) is 50/5.
0 or more and less than 82/18, preferably 55/45 to 8
Less than 2/18, more preferably 60/40 to 82/
Examples include less than 18. If the molar ratio is 82/18 or more, which is a large amount of ethylene units, the vulcanizate from the composition of the present invention will lose its rubbery properties at low temperatures, and the use of copolymer rubber A will lose its significance. Moreover, if the molar ratio is smaller than 50/50, the strength of the vulcanizate will be low. The α-olefin which is a component of the ethylene/α-olefin copolymer rubber B used in the present invention is an α-olefin having 4 to 10 carbon atoms.

Specifically, 1-butene, 1-benzene, 1-hexene,
Examples include 4-methyl-1-benzene, 1-octene, 1-decene, and mixtures thereof, with 1-butene being particularly preferred. The molar ratio of ethylene units and α-olefin units (ethylene/α-olefin) is 82/1.
8 to 95/5, preferably 83/17 to 95/
5, more preferably 85/15 to 95/5. The number of carbon atoms in the α-olefin of the copolymer rubber B of the present invention and the molar ratio of ethylene to α-olefin are important requirements for the constitution of the present invention. That is, α of copolymer rubber B
- The use of propylene as the olefin component is excluded from the invention due to the low strength of the vulcanizates from the compositions of the invention.
If the molar ratio is greater than 95/5, that is, there are many ethylene units, the vulcanizate from the composition of the present invention may lose rubber properties such as increased hysteresis loss, increased compression set, and decreased flexibility, or Disadvantages such as difficulty in homogeneous mixing with copolymer rubber A occur, and if it is less than 82/18, the strength of the vulcanizate from the composition of the present invention is low and the use of copolymer rubber B loses its meaning. . Intrinsic viscosity [η] of each of the ethylene/α-olefin copolymer rubbers A and B of the present invention
is 0.6 to 6.0 d1/f1, preferably 0.8 to 4.0 d1/7, more preferably 0.8 to 3.0, as a value measured by a multipoint method at 135°C in decalin.
d1/t.

If [η] is less than 0.6dj/f, the strength of the vulcanizate will be low, or 6.0d1/? If the above is the case, the process of producing a vulcanizate described later, for example, the roll processability in the roll processing process for preparing the unvulcanized compounded rubber, and the fluidity in the process of molding the compounded rubber into the intended shape. This causes problems in the production of vulcanizates, such as deterioration of moldability. The ethylene/α-olefin copolymer rubbers A and B used in the present invention do not need to contain a polyene component, but preferably contain one.

The content of the polyene component is 4 to 50, preferably 4 to 401, and more preferably 4 to 30 in terms of iodine value. Particularly when a sulfur compound is used as a vulcanizing agent, a polyene component is essential. Specifically, the polyene component includes 1,4-hexadiene, 1,6-octadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, and 7-methyl-1,6-octadiene. Chained nonconjugated diene, cyclohexadiene, synclopentadiene, methyltetrahydroindene, 5-vinylnorbornene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2-norbornene, 6-chloromethyl Cyclic non-conjugated dienes such as -5-isopropenyl-2-norbornene, 2,3-diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-
Representative examples include trienes such as norbornene, 2-propenyl-2,2-norbornadiene, 1,3,7-octatriene, and 1,4,9-decatriene. Preferred polyenes include cyclic non-conjugated dienes and 1
- 4-hexadiene, especially synchlopentadiene or 5-ethylidene-2-norbornene. Incidentally, a combination in which both copolymer rubber A and copolymer rubber B contain a polyene component is extremely preferable.

Such copolymer rubber A is produced by a conventionally known method, and copolymer rubber A in which the α-olefin is propylene is commercially available. Further, the ethylene/α-olefin copolymer rubber B used in the present invention can be produced by a conventional method for producing ethylene/propylene copolymer rubber.

That is, in a medium, ethylene,
It is produced by supplying an α-olefin having 4 to 10 carbon atoms, optionally a polyene, J, and hydrogen gas as a molecular weight regulator.

Examples of the medium include pentane, hexane, heptane,
Octane, aliphatic hydrocarbons such as kerosene, alicyclic hydrocarbons such as cyclohexane, aromatic hydrocarbons such as benzene, toluene, xylene, chlorobenzene, carbon tetrachloride, tetrachlorethylene, trichlorethylene, ethyl chloride , methylene chloride, dichloroethane and the like can be used alone or in combination. Examples of soluble vanadium compounds include vanadium tetrachloride, vanadyl trichloride, vanadium triacetylacetonate, vanadyl acetylacetonate,
Vanadyl trialkoxide VO (0R) 3 (R in this momme)
represents an aliphatic hydrocarbon group. ), halogenated vanadyl alkoxide VO(0R)NX3. , n (where R is an aliphatic hydrocarbon group, X is a halogen atom, and O<n<3.

) can be used alone or in combination. On the other hand, as an organoaluminum compound, the general formula RmAlX3
-n1 (wherein X ('R is an aliphatic hydrocarbon group, Dichloride etc. can be used alone or in combination.In the present invention, the most important requirement for the constitution of the present invention is to use such copolymer rubber A and copolymer rubber B together.

Copolymer rubber A imparts rubbery properties, especially rubbery properties at low temperatures, to the vulcanizate of the composition of the present invention, and copolymer rubber B imparts strength to the vulcanizate. Thus, the vulcanizates from the compositions of the invention have both strength and rubbery properties, especially at low temperatures. The blending ratio of copolymer rubber A and copolymer rubber B can be arbitrarily selected depending on the use of the composition of the present invention, but usually the weight ratio (A/B) is 5/95 to 95/5,
Preferably it is 10/90 to 90/101, more preferably 20/80 to 90/10.

If the weight ratio (A/B) is less than 5/95, the amount of copolymer rubber A is small and the amount of copolymer rubber B is large, the vulcanizate loses its rubbery properties at low temperatures, and the weight ratio (A/B) decreases. If B) exceeds 95/5 and the amount of copolymer rubber A is large and the amount of copolymer rubber B is small, the strength of the vulcanizate will be low and the effects of the present invention will not be achieved in either case. When obtaining a vulcanizate from the composition of the present invention, in addition to copolymer rubber A and copolymer rubber B, rubber reinforcing agents, fillers, The type and amount of the softening agent, the type and amount of compounds constituting the vulcanization system such as the vulcanizing agent, vulcanization accelerator, and vulcanization aid, and the process for producing the vulcanizate are selected as appropriate. .

In the present invention, the total amount of copolymer rubber A and copolymer rubber B in the composition is appropriately selected depending on the intended performance and use of the vulcanizate, but is usually 20% by weight or more, preferably 25% by weight. That's all.

The softening agents that can be used in the present invention include those commonly used for rubber, such as process oils, lubricating oils,
Petroleum-based softeners such as paraffin, liquid paraffin, petroleum asphalt, and petrolatum, coal tar-based softeners such as coal tar and coal tar pitch, fatty oil-based softeners such as linseed oil, rapeseed oil, and bean oil, and tall oil. : Sub: Waxes such as beeswax, carnauba wax, and lanolin; Fatty acids and fatty acid salts such as ricinoleic acid, palmitic acid, barium stearate, calcium stearate, and zinc laurate; Petroleum resins, atactic polypropylene, coumaron indene resins, etc. Examples include synthetic polymeric substances.

Among these, petroleum-based softeners are preferably used, and process oils are particularly preferred. The blending amount of these softeners is appropriately selected depending on the use of the vulcanizate, but usually the total amount of copolymer rubber A and copolymer rubber B is at most 150 parts by weight, preferably at most 100 parts by weight. 100 parts by weight is blended. In the present invention, SRF. G.P.F. FEF. HAF,
ISAF,. SAF,. FT,. Rubber reinforcing agents such as carbon black such as MT and finely divided silicic acid and fillers such as light calcium carbonate, ground calcium carbonate, talc, clay, etc. may be used.

The type and amount of these rubber reinforcing agents and fillers are appropriately selected depending on their use, but at most 300 parts by weight, preferably at most 200 parts by weight, based on 100 parts by weight of the total amount of copolymer rubber A and copolymer rubber B. It is blended in the ratio of 1 part. The weight ratio (A/B) of copolymer rubber A and copolymer rubber B is 60.
/40 to 5/95 and a relatively large proportion of copolymer rubber B, the vulcanizate will have sufficient strength even if a large amount of an extremely inexpensive filler is blended within the above range. It has the important advantage of being able to provide a vulcanizate having the same strength as a propylene copolymer rubber vulcanizate at a lower cost. The vulcanized product from the composition of the present invention is produced by preparing an unvulcanized compounded rubber by the method described below, and then molding the compounded rubber into the intended shape, in the same way as when vulcanizing general rubber. Manufactured by post-vulcanization.

As a vulcanization method, there are a method of heating using a vulcanizing agent and a method of irradiating with an electron beam. Examples of the vulcanizing agent used include sulfur compounds and organic peroxides. Examples of the sulfur-based compound include sulfur, sulfur chloride, sulfur dichloride, morpholine disulfide, alkylphenol disulfide, tetramethylthiuram disulfide, and selenium dimethyldithiocarbamate, among which sulfur is preferably used. The sulfur-based compound is the total amount of the copolymer rubbers A and B of the present invention, 100%
It is used in a proportion of 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight. Examples of organic peroxides include digyl peroxide, 2,5-dimethyl-
2,5-di(tert-butylperoxy)hexane, 2,5
-dimethyl-2,5-di(benzoylperoxy)hexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane-3, di-tert-butyl peroxide, di-tert-butyl peroxy-3,3 Examples include 5-trimethylcyclohexane and tert-butyl hydroperoxide, among which digmyl peroxide, di-tert-butyl peroxide, and di-tert-butyl peroxy-3,3,5-trimethylcyclohexane are preferably used. The organic peroxide is used in an amount of 3.times.10@-4 to 5.times.10@-2 mol parts, preferably 1.times.10@-3 to 3.times.10@-2 mol parts, per 100 parts by weight of the copolymer rubbers A and B of the present invention. When using a sulfur compound as a vulcanizing agent, it is preferable to use a vulcanization accelerator in combination.

As a vulcanization accelerator, N-cyclohexyl-2-benzothiazole sulfenamide, N-oxydiethylene-
2-benzothiazole sulfenamide, N-N-diisopropyl-2-benzothiazole sulfenamide, 2-mercaptobenzothiazole, 2-(2,4-dinitrophenyl)mercaptobenzothiazole, 2-(
Thiazole series such as 2,6-diethyl-4-morpholinothio)benzothiazole and dibenzothiaziru disulfide: diphe5-nylguanidine, triphenylguanidine, diorthotolylguanidine, orthotolyl biguanide, diphenylguanidine phthalate Guanidine series such as: acetaldehyde aniline reactant,
Butyraldehyde-aniline condensates, 1 Aldehyde amines or aldehyde-ammonia systems such as xamethylenetetramine and acetaldehyde ammonia; Imidazolines such as 2-mercaptoimidazoline: thiocarbanilide, diethylthioeria, dibutylthioeria,
Thioeria series such as trimethyl l-thioeria and diorthotolyl thioeria: tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, pentamethylene thiuram tetonilatrasulfide Thiuram series such as: zinc dimethyldithiocarbamate, zinc diethylthiocarbamate, zinc di-n-butyldithiocarbamate, zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate, selenium dimethyldithiocarbamate, diethyl Dithioate salts such as tellurium dithiocarbamate; xanthate systems such as zinc dibutylxanthate; and zinc white. These vulcanization accelerators are used in an amount of 0.1 to 20 parts by weight, preferably 0.2 to 10 parts by weight, based on 100 parts by weight of the total amount of copolymer rubbers A and B. When using an organic peroxide as a vulcanizing agent, it is preferable to use a vulcanizing aid in combination.

Vulcanization aids include sulfur, quinone dioxime types such as p-quinone dioxime, methacrylate types such as polyethylene glycol dimethacrylate, diallyl phthalate,
Examples include allylic compounds such as triallyl cyanurate, other maleimide compounds, and divinylbenzene. Such a vulcanization aid is used in an amount of 1/1 mole of organic peroxide used.
2 to 2 moles, preferably equivalent moles are used. When using an electron beam as the vulcanization method without using a vulcanizing agent, 0.1 to 1
0 MeV (megaelectron volt), preferably 0.
Electrons having an energy of 3 to 2.0 MeV may be irradiated at an absorbed dose of 0.45 to 35 Mrad (mechalat), preferably 0.5 to 10 Mrad.

At this time, a vulcanization aid may be used in combination with the organic peroxide as the vulcanizing agent, and the amount thereof is 1 x 10 -
4 to 1X10-1 molar parts, preferably 1X10-3
to 3×10 −2 mole parts. Unvulcanized compounded rubber is prepared by the following method.

That is, copolymer rubbers A and B, fillers, and softeners were mixed at 80 to 170 m using a mixer such as a Banbury mixer.
After kneading at a temperature of 3 to 10 minutes at a temperature of 3 to 10 minutes, a vulcanizing agent and, if necessary, a vulcanization accelerator or vulcanization aid are further mixed using rolls such as oven rolls, and the roll temperature is 40 to 80 °C. After kneading at ℃ for 5 to 30 minutes, a ribbon-like or sheet-like compounded rubber is prepared, or the weight ratio (A/B) of copolymer rubber A and copolymer rubber B is 60/4.
When the blending ratio of copolymer rubber B is high, 80 to 10% of the copolymer rubber and other compounding agents are added instead of the kneading process using the mixers and rolls described above.
Feed directly to an extruder heated to 0°C, with a residence time of 0.
Pellet-like compounded rubber may be prepared by setting the time to 5 to 5 minutes. The compounded rubber thus prepared is molded into the desired shape using an extruder, calendar roll, or press, and at the same time as the molding or the molded product is introduced into a vulcanization tank and heated at a temperature of 150 to 270°C. A vulcanizate can be obtained by heating for 30 minutes or by irradiating with an electron beam according to the method described above. This vulcanization step may be carried out using a mold or without a mold. When a mold is not used, the molding and vulcanization steps are usually carried out continuously. Of course, when vulcanization is performed by electron beam irradiation, a compounded rubber containing no vulcanizing agent is used.

Further, as a heating method in the vulcanization layer, a heating layer such as hot air, glass bead fluidized bed, UHF (ultra high frequency electromagnetic wave), steam, etc. can be used.

The vulcanized product produced as described above can function as an electrical insulation material, automotive exterior parts, loop ink, hoses such as automotive radiator hoses, or can be used as a foaming agent for the unvulcanized compounded rubber. When blended with , a foam is produced that functions as a heat insulating material, cushion material, sealing material, etc. When producing an electrical insulating material from the composition of the present invention, the volume resistivity of the vulcanizate is 1 x 1010Ω.
・? Since the above is preferable, it is recommended to use a non-conductive filler as the filler.

If carbon black is unavoidably used, add 2 parts by weight to 100 parts by weight of the total amount of copolymer rubber A and copolymer rubber B.
The amount is 5 parts by weight or less, preferably 15 parts by weight or less. or,
Various compounding agents should be selected so that the breaking point and tensile strength of the vulcanizate are 50 kg/Cd or more. In order to increase the strength of conventional ethylene-propylene copolymer rubber vulcanizates, it was necessary to incorporate a considerable amount of carbon black, which resulted in loss of electrical insulation properties, but the composition of the present invention Since the strength is sufficiently high even without using carbon black, a high-strength electrical insulating material with good electrical insulation properties can be obtained. Of course, calcium carbonate and talc clay, which significantly impair the strength of vulcanized rubber for ordinary ethylene-propylene copolymer rubber, are non-conductive fillers, so they are not sufficient when used in the composition of the present invention. A high strength electrical insulation material is obtained and is preferably used. Thus, the composition of the present invention can be used in electrically insulating caps around automobile engines such as plug caps, ignition caps or distributor caps, condenser caps, and current-carrying parts of electric wires such as marine electric wires or automobile ignition cables. An insulating layer covering a cylindrical shape and an electrical insulating material such as a cable joint cover are manufactured by conventionally known processes.

Furthermore, automobile exterior parts such as bumpers, bumper fillers, bumper strips, bumper side guards, overriders, and side protection moldings can be manufactured from the composition of the present invention, and these automobile exterior parts can be manufactured using the composition of the present invention. It has the same effect as the vulcanizate made from the composition of
The strength is sufficiently high even without the use of carbon black, so it can be solved by appropriately using pigments.

Furthermore, in order to produce a foam from the composition of the present invention, a blowing agent and, if necessary, a blowing agent is added. The blowing agents used include inorganic blowing agents such as sodium bicarbonate, sodium carbonate, ammonium bicarbonate, ammonium carbonate, ammonium nitrite; Nitroso compounds such as N-dimethyl N-marginitroso terephthalamide, N-marginitroso pentamethylene tetramine; azodicarbonamide, azobisisobutyronitrile, azicyclohexylnitrile, azodiaminobenzene, barium.
Azo compounds such as azodicarboxylate: benzene,
Sulfonyl hydrazide compounds such as sulfonyl hydrazide, toluene sulfonyl hydrazide, PV oxybis(benzenesulfonyl hydrazide), diphenylsulfone-3,3'-disulfonyl hydrazide:
Examples include azide compounds such as calcium azide, 4,4'-diphenyl disulfonyl azide, para-toluene malhonyl azide, and the like. Among them, nitroso compounds, azo compounds and azide compounds are preferably used. Such a blowing agent is used for copolymer rubber A. Total amount of B 1
By adding 0.5 to 30 parts by weight, preferably 1 to 20 parts by weight, a foam having an apparent specific gravity of 0.03 to 0.7 is produced. Further, a foaming aid may be used in combination with a foaming agent if necessary.

A foaming aid is an additive that functions to lower the decomposition temperature of a foaming agent, promote decomposition, and make cells uniform. Examples of foaming aids include organic acids such as salicylic acid, phthalic acid, and stearic acid: urea and its derivatives. For the process of obtaining a foam from the composition of the present invention, a conventional process for producing a foam from a conventional ethylene-propylene-polyene copolymer rubber can be used. The foam made from the composition of the present invention has an apparent specific gravity of D and a tensile stress at break of TB (K
g/Cd), it is possible to achieve a high specific strength of 100k9/d or more, which is determined by TB/D (Kg/Cd), and is suitable for heat insulation materials, electrical insulation materials, flotation materials, and cushion materials. , can be used for soundproofing materials, etc. The present invention described in detail above will be specifically explained below using Examples.

Examples 1, 2, 3, Comparative Examples 1, 2 The molar ratio of ethylene units to propylene units (ethylene/propylene) is 65/35, and [η] measured with a decalin solvent having an iodine value of 101135°C is 1.72 d1/ f ethylene/propylene/5-nitylidene-2-norbornene copolymer rubber (copolymer rubber A), the molar ratio of ethylene units and 1-butene units (ethylene/1-butene) is 90
/10, iodine value is 10, [η] measured by the above method is 1,35 (11/7 ethylene/1-butene/5-ethylidene-2-norbornene copolymer rubber (copolymer rubber B)
, zinc white, rubber reinforcing agent, and softener according to the blending ratios in Tables 11 and 2 using a Banbury mixer of 4.31 (0
The mixture was kneaded for 6 minutes using a 0C type (manufactured by Kobe Steel, Ltd.).

Subsequently, using an 8 x 20 inch open roll, vulcanizing agent and vulcanization accelerator 1 were further mixed in the proportions shown in Table 1, and kneaded for 5 minutes at a roll temperature of 60°C to obtain a compounded rubber of 1k9.
I got it.

This compounded rubber was heated for 30 minutes under a press pressure of 100 kg/Cd using a hot press heated to 160°C to prepare a vulcanized sheet and a sample for compression set measurement.

The obtained vulcanized sheet and sample for compression set measurement were
After being left in a constant temperature room at 25°C for 4 hours, the vulcanized rubber was tested to determine the hardness, tensile stress at break TB (K9/Cd), tensile elongation at break EB (%), and compression 2 permanent set CS (%). ) were measured respectively.

The results are shown in Table 2. Each measurement method is as follows.

Hardness: Six of the above sheets were stacked and measured using a type A tester according to the method described in JIS K63Ol Physical Testing Method for Vulcanized Rubber, Section 5.2 Spring Type Hardness Test.

TB and EB: A No. 3 tamper test piece described in JIS K63Ol was punched out from the sheet, and the test piece was subjected to 500°C at 25°C according to the method specified in JIS Section 3.
TB and EB were measured at a tensile rate of mm/Mm*.

Compression set CS: The method described in JIS K63Ol was followed.

However, the heat treatment temperatures were 25°C and -20°C. Comparative Example 3 In Example 2, instead of copolymer rubber A, the molar ratio of ethylene units and propylene units (ethylene/propylene) was 90/10, and the iodine number was 101 [η] was 1.73 d.
1/7 ethylene propylene 5-ethylidene-2-
The same operation as in Example 2 was performed except that norbornene copolymer rubber was used.

The results are shown in Table 2. Example 4, Comparative Example 4 The same operations as in Example 1 were performed except that copolymer rubber A and copolymer rubber B of Example 1 and other compounding agents were used in the proportions shown in Table 3.

The results are shown in Table 3. The results of Examples 1, 2, 3, and 4 show that the vulcanizate from the composition of the present invention has high strength and considerable rubber-like properties at low temperatures, and is suitable for manufacturing automobile exterior parts. .

Example 5, Comparative Example 5 The same operation as in Example 1 was carried out except that copolymer rubber A and copolymer rubber B of Example 1 and other compounding agents were used in the proportions shown in Table 4, and the obtained additives were The volume resistivity of sulfur was measured.

The results are listed in Table 4. Incidentally, the volume resistivity was measured at 200V and 25°C using the direct polarization method.

The results of Example 5 show that an excellent electrical insulating material can be obtained from the composition of the present invention.

Claims (1)

[Claims] 1. The molar ratio of ethylene units to α-olefin units having 3 to 10 carbon atoms (ethylene/α-olefin) is 50.
/50 to less than 82/18 and the molar ratio of ethylene units to α-olefin units having 4 to 10 carbon atoms (ethylene/α-olefin copolymer rubber A)
The weight ratio of copolymer rubber A and copolymer rubber B (copolymer rubber A/copolymer rubber A rubber composition for vulcanization, characterized in that polymerized rubber B) is 5/95 to 95/5. 2. The composition according to item 1, wherein the α-olefin of copolymer rubber A is propylene. 3. The composition according to item 1 or 2, wherein the α-olefin of copolymer rubber B is 1-butene. 4 Intrinsic viscosity of copolymer rubber A and copolymer rubber B [η]
3. The composition according to any one of items 1 to 3, characterized in that: 0.6 to 6 dl/g, respectively. 5. The composition according to any one of items 1 to 4, wherein copolymer rubber A and copolymer rubber B each contain a polyene component having an iodine value of 4 to 50.